From across the pond he came up with the idea of taking fatbiking to Chamonix to attempt the first winter Tour du Mont Blanc on wheels. “I wanted to go somewhere iconic for snowsports. I wanted to get the bike in amongst the hardcore of Chamonix, and showcase the sport” he told me.

But his biggest challenge was the weather. He’d always known it would be either an early or late season trip – there is simply too much unconsolidated snow mid-season – but December was a write-off for skiers and fatbikers alike.

“It got towards the last week of ‘winter’” Harper recalls, “and I started to feel the pressure, because I’d touted this as a winter trip. I wanted, at least, to set off before spring but I couldn’t find a five day weather window. It started to suck the energy out of me a bit, because every day was a day I wasn’t doing it. So I found a window of 3 good days and decided to set off.

What Harper couldn’t have prepared for was the way the mountain magnifies every minor problem to the point of desperation.

“I took the fall line into a steep valley that I couldn’t see the end of. It went against everything I’ve ever learned.”

“I woke up in a cold sweat. I didn’t know if my sleeping bag was too warm, but that’s how I sold it to myself. I’d picked up a slight bug a few days before, but out of frustration I’d ignored that basic human message that I shouldn’t be doing anything strenuous.

“I found I couldn’t eat, so I knew it wasn’t going to be the best day, but I’d trained for this scenario. This was the first big hurdle of the trip. Am I going to bail out empty handed or push through? I pushed into a 10 hour day over to the Refuge du Bonhomme and arrived exhausted, feverish and running out of fuel. I still hadn’t eaten.

“And then a storm came in.”

“I could see the valley below. I could see a direct line of sight between me and safety. I overruled my trace and took the fall line into a really steep valley that I couldn’t see the end of. It goes against everything I’ve ever learned.”

In the US, Harper had spent time working with Portland Mountain Rescue and had learned the dangers of taking an unknown fall line. Most of their call outs are to hikers following their noses from the summit of Mount Hood.

Harper had also agonised over his route, combining local beta, satellite imagery and traditional mapping, which he was following through a trace on his Suunto watch. What forced this preparation out of his mind – whether it was hunger, sickness, altitude or animal instinct – will be a question he’ll ponder for years to come.

“I got to a point, above a cliff band, where I realised there was no way out,” he remembers. “I was on the side of that mountain, in a gully, completely on my own with a bike and a heavy pack. I was scared out of my mind. I thought about my family.

“There was no way out. I was scared out of my mind. I started to think of my family…”

“I used the bike” says Harper. “I was on my knees with my snowshoes pointed into the snow, moving the bike a foot at a time and shuffling up towards it. I was moving diagonally because it was too steep to go straight up, and I was slamming the handle bar through the ice, the other features of the bike would imprint into the ice and bite enough for me to pull up on the frame.

“I guess it took me at least an hour to climb out, but I wasn’t thinking about anything. I almost don’t remember it.”

With a blank mind and a shattered body, Harper made it out of the gully and followed his trace until it led him to a safer descent. He arrived in the town of Les Chapieux hoping for human contact after his lonely ordeal, only to find the town deserted for winter. But he shivered the night away in a refuge which must have felt like a palace, before descending the next day as far as Bourg St Maurice and safety.

Harper is already planning his next attempt and seems almost grateful that things turned out this way. “There’s a natural law” he tells me “and I submit to that. Something was telling me ‘this is not the time; there’s something here for you but there’s an evolution you need to have,’ and the retrospective nature of ‘failure’ gives you that evolution.

“I’m earning it. These moments of ‘failure’ are actually just part of the story. They’re just steps. If I’d banged it out easily it would’ve simply checked my ego box. But what it’s done is call my bluff.”

Harper found some reserves, down in that gully, that allowed him to climb over a fever, over hunger and out to safety. And he will go again. I don’t think he’s bluffing.

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